Core drilling apparatus



NOV- 24. 1953 v. J. DEvlNE ETAL 2,660,402

CORE DRILLING APPARATUS Filed Dec. 19, 1949 3 Sheets-Sheet l Gttornegs V. J. DEVINE ETAL CORE DRILLING APPARATUS Nov. 24, 1953 5 Sheets-Sheet 2 Filed Dec. 19, 1949 Gttornegs Nov. 24, 1953 v. J. DEVINE ErAL CORE DRILLING APPARATUS 3 Sheets-Sheet 3 Filed Dec. 19, 1949 l I nventors Vera/ 1/ @er/)7e and B, an/rence 1./ @ev/)7e Qttorncgs Patented Nov. 24, 1953 UNITED STATE i'i'TENT OFFICE CORE DRILLING APPARATUS Verbol J. Devine and Lawrence V. Devine, Kansas City, Mo.

3 Claims.

This invention relates to a drilling apparatus such as used in exploration of earth formations at substantial depths and for drilling wells into producing formations. Usually such an apparatus includes a drill bit mounted on the lower end of a string of drill pipe having a Kelly or drive rod on its upper end which is rotated by a power mechanism located above ground to effect turning of the drill bit. Simultaneously a drilling fluid is circulated downwardly through the string of drill pipe to lubricate the drill bit and wash the cuttings to the top of the bore hole. As the hole progresses, additional strings of drill pipe are added as required to maintain connection between the rotating mechanism and the drill bit.

Many difculties are encountered with such apparatus particularly when drilling at substantial depths due to deflection of the drill bit from a straight course caused by whipping and bending of the drill pipe, diiculty of controlling weight of the drill pipe on the bit in accordance with the drilling speed through the various formations, twisting off of the drill pipe joints and many other reasons well known to those experienced in drilling earth formations. In order to reduce such hazards the equipment is being made heavier and stronger which renders the handling thereof more difficult as well as requiring greater motive power in effecting operation thereof. Prior to the present invention it has been proposed to eliminate many of the usual difficulties by rotating the drill bit through a motor that is carried by the lower end of the drill pipe for rotating the bit. However, such mechanism precludes the taking of cores of the earth formation progressively with the drilling and interferes with the running in and out of various instruments, tools, and the like through the drill pipe, as when coring a head of the drill bit to test pressures and obtain advance knowledge of the lower formations before penetration thereof by the larger bit.

It is, therefore, the principal object of the pres' ent invention to provide a drilling apparatus with a motor unit that is mounted on the lower end of the drilling string and directly connected with the drill bit but which is constructed to provide an axial passageway therethrough of ample size for passing a core and performing other operations that may be required in the drilling of `a bore hole.

Other objects of the invention are to provide a. motor unit that is of simple construction and which has the working parts thereof located exteriorly of the axial passageway but within the scope of a standard drill bit, and to provide a drilling apparatus that permits the use of nonrotating light weight drill pipe.

It is also an object of the invention to provide a drilling apparatus including a bottom hole motor wherein the core may be removed through the inner drill pipe without pulling the drilling string, thereby saving in drilling time and reducing the cost of the operations.

In accomplishing these and other objects of the invention as hereinafter pointed out, we have provided improved structure the preferred forms of which are illustrated in the accompanying drawings wherein:

1 is a vertical section through the lower portion of a drilling string showing a core bit actuated by a motor in accordance with the present invention.

Fig. 2 is a perspective view of the motor and core bit in disassembled spaced relation. Parts of the motor being broken away to better illustrate the construction.

Fig. 3 is a perspective View of the motor parts shown in disassembled spaced relation.

Fig. 4 is a cross-section on the line 4-4 of Fig. l particularly illustrating the intake channels to the motor.

Fig. 5 is a cross-section on the line 5-5 of Fig. l particularly illustrating the exhaust channels.

Fig. 6 is a cross-section through the motor on the line 6--6 of Fig. 1 showing one position of the rotor and its operating vanes.

Fig. 7 is a similar cross-section showing another position of the rotor and operating vanes therefor.

Fig. 8 is an enlarged fragmentary section through the rotor and stator particularly illustrating details of the vanes.

Fig. 9 is a side elevational view of a modified form of the invention a portion of the motor being shown in section.

Referring more in detail to the drawings:

l designates a bore hole that is being drilled through an earth formation 2 by means of a drilling apparatus constructed in accordance with the present invention and which includes inner and outer strings of pipe 3 and 4 which are usually composed of sections interconnected by conventional tool joints or couplings not shown. The inner pipe 3 is of smaller external diameter than the inner diameter of the outer pipe 4 to provide an annular downow passageway 5 through which a drilling fluid is circulated from above ground for actuating a drilling motor E and to carry cuttings made by a drill bit l upwardly through the inner pipe 3 to the top of the ground.

The motor 6 and drill bit 1 constitute the principal feature of the present invention in that they are constructed to form and pass a core upwardly through the inner pipe 3 and to provide a passageway completely through the drilling string for insertion of ,various instruments and other devices incidental to drilling and coring of a bore hole.

The motor 6 includes a stator 8 and rotor 9. In the preferred form of the invention illustrated in Figs. l to 8 inclusive, the stator is directly connected to the outer pipe 4 and is supported in stationary position therewith. The rotor 9, however, is rotatably mounted with respect to the inner stationary pipe 3 to effect rotation .of the drill bit 1, which is directly connected with the rotor. However, the drill bit may be connected with the rotor through one or more joints of drill pipe if desired.

The stator 8 includes a sleevelike body having an outer `diameter substantially conforming to the outer diameter of the bit 1 and having an inner axial bere l Containing crGumferentall-y spaced inserts II which are welded or otherwise secured within the inner bore of the stator to provide pressure chambers I2 therebetween that are of arcuate cross section and have curving sides I3 and I4 joining the outer curved faces I5 of the chambers with the inserts. The curved sides thus provide cam portions for controlling movement of the rotor vanes as later described. The inserts II are o f such cross-sectional width as to provide arcuate sealing faces I6 for contact with the rotor 9 and prevent leakage of iiuid from one of the pressure chambers to the other.

Extending longitudinally of the wall of the stator in parallel relation with the axis of the rotor are pressure fluid intake channels I1 hav*- ing slot-like outlets I8 opening through the faces I of the stator chambers adjacent the juncture of the cam portions I3 with the faces I5 of the chambers I2 as best shown in Figs. 6 and 7 Located intermediate the intake channels I1 are similarly arranged exhaust channels I9 having slot-like ports located adjacent the juncture of the cam surface I4 with the outer surface I5 of the chambers for escape for the pressure fluid.

The ends 2| and 22 of the stator are of reduced diameter and externally vthreaded as at 2,3 and 24 to mount couplings rings. 2 5 and 26 f;

respectively. The upper coupling 25 includes an internally threaded depending flange thatis engaged with the threads 23 and an upwardly ex-Y tending externally threaded flange 28 engaged by the internal threads of the outer pipe 4. coupling also includes an inwardly extending annular plate portion 29 to close the upper ends of the exhaust channels and to engage the rotor as later described. The lower coupling 26 is similarly formed in that it is provided with an upwardly extending internally threaded flange 30 engaged with the threads 24 on the lower end of the stator, and an inwardly extending annular plate portion 3I that closes the lower ends of the intake channels I1. The plate portion 279 is provided with ports 32 in registering with the upper ends of the intake channelsI to permit entrance ofthe drilling fluid for operating the motor. The plate portion of the lower coupling is provided with exhaust ports 32'l in registry with the exhaust channels i9 for discharge of the drilling fluid through the bit.

The rotor 9 includes an elongated cylindrical body 33 having reduced threaded ends 34 and 35 which form annular shoulders 3B and 31 in The Y registry with the ends of the stator, for engage4 ment between plate portions of the coupling rings 25 and 26, whereby the rotor is centered with respect to the stator and retained from axial movement therein. Formed within the outer circumferential outer face 38 of the rotor are a plurality of circumferentially spaced vane receiving pockets 39 that extend longitudinally of the rotor. The pockets 39 are of groove-like character and have substantially shallow bottom portions 40 that extend at an angle from undercut lips 4I to provide bearing sockets 42 for edges of the vanes as later described. The bottom portions 40 cooperate with similar bottom por tions 43 that form obtuse angles therewith as at 44 to provide deeper portions for the grooves to accommodate head portions of the vanes. The sides 45 of the pockets opposite the vane sockets are formed on arcs generated from the bearing sockets 42 whereby the heads of the vanes may swing outwardly from vthe pockets into the pressure chambers I2 ofuthe stator. The arcuate sides 45 Vterminate short of the circumferential face 38 of the rotor vto form recesses 46 to a accommodate lip portions on the vanes as later described.

The vanes 41 substantially conform to cross sectional shape with the pockets of thc rotor and have arcuate outer faces 48 conforming to the outer curvature of the rotor, and which are adapted to make Contact with the cam portions at the sides of the stator chambers. The opposite faces of the veins are formed on angular planes substantially corresponding with the bottoms of the pockets to provide a relatively thick head portion 49 on the retractive sides thereof and which serve as theeffective surfaces against which the drilling fluid acts to effect rotation of the rotor. Head portions of the vanes are also formed on arcs corresponding with the curvature of the side faces 45 of the pockets so that they swing outwardly to bring lip portions 49 thereof into sealing contact with the outer faces of the rotor chambers, the head portions being sufficiently thick to maintain contact with the rotor and prevent leakage under the vanes. `The ylip portions 49' are shaped to be received within the recesses 46 of the pockets and provide initial entrance spaces 50 for the pressure fluidl as the vanes uncover the intake slots 20 of the stator. The opposite edges of the outer surfaces of the vanes may be also relieved as indicated at 5I ,to permit outward swinging movement thereof under the lip portions 4I of the pockets.

In order to normally urge the vanes outwardly into the contact with the outer surfaces I5 of the stator chambers, the `bottom of each pocket at the deeper side thereof is provided with one or more spring sockets 52 for seating springs 53 that bear withinspring seats 54 ofthe respective vanes.

Mounted on the reduced end of the rotor is an internally threaded collar-55 having an outwardly extending annular flange 56 that @Operates With the shouldered end of the rotor in engaging the respective ring-like plate portion of the upper coupling as best shown inFig. 1. The iiange 56 also provides the lower `race 51 forlantifriction bearings 58 which roll against an upper race 59 that is, provided by an inwardly extending flange 6,0 attached to. and` extending inwardly from the inner face of the vinner pipe 3 a point above the lower end thereof.

The rotor is thus connected with the inner 5 pipe in such a manner as to prevent longitudinal movement thereof but to permit free rotation under weight of the inner pipe.

Core bit 1 includes a ringlike body 6I having an outer face 62 substantially comforming to the outer diameter of the stator and an inner face B3 substantially conforming at its upper end with 'the inner diameter of the rotor but which tapers downwardly and inwardly to provide a seat 64 for a core catcher 65. Below the seat for the core catcher, the inner face of the bit extends downwardly in cylindrical form to provide an inner reaming face 66 joining with an end drilling face 61. The outer circumference of the bit also forms reaming face 58. The rearning and drilling faces are inlaid with cutting elements such as diamonds 69 or other forms of abrasive devices. The upper end of the drill bit has an annular groove 10 in communication with the exhaust ports I9 of the motor, for distributing drilling fluid to channels 1I for supplying the drilling fluid to outlet ports 12 leading through the respective drilling faces of the bit as best shown in Fig. 1.

In order to prevent leakage between the bit 1 and motor 6 the lower coupling 26 carries an annular rib 13 that engages in an annular groove 14 in the bit 1 that is located on the outer side of the distribution groove 10. The inner circumference of the rotor 9 may be provided with longitudinal grooves 9 for receiving keys or splines of various instruments or tools that may be run through the inner pipe 3 and used ahead of the drill bit, for example, a small core barrel (not shown) when taking a core ahead of the bit.

In using the apparatus the outer pipe 4 is connected with the discharge of a pressure pump (not shown) to supply drilling fluid to the downilow passageway 5 between the pipes 3 and 4. The upper end of the inner pipe 3 is connected with a slush pond where the cuttings and parts of core are separated out and the fluid is returned to the pressure pump.

In starting a bore hole, the inner and outer pipes 3 and 4 are respectively connected with the rotor 9 and stator 9 elements of the motor 6. The bit 1 is connected to the rotor 9 by engaging the internal threads thereof with the lower threaded end 35 of the rotor and to bring the sealing groove 14 into engagement with the annular sealing rib 13. If no core is to be taken, an ordinary drilling bit may be substituted for the core bit shown in the drawings.

When the drilling fluid is forced downwardly through the outer passageway 5, it enters the l motor 6 through the intake ports 32 and passes downwardly through the intake channels I1 from where it is discharged through the slot-like ports I8 (Fig. 6) into the pressure chambers I2 of the motor. The Vanes 41 enter the pressure chambers I2 and swing outwardly responsive to action of the compression springs 53, supplemented by the pressure fluid acting under the lips 49 which brings the head portions 49 of the vanes into position to be acted upon by the pressure fluid to effect a clockwise rotation of the rotor as illustrated in Figs. 6 and 7. When the vanes 41 pass the ports 20 of the outlets IB, the pressure uid that becomes trapped thereahead is discharged through the exhaust ports because the preceding vanes have uncovered the exhaust ports to expell the drilling fluid into the exhaust channels I9 to the water courses 1I and 12 in the drill bit. After the vane 41 passes the slot-like exhaust ports 20, the curved rear edge thereof contacts the curved cam surfaces I4 which press the vanes back into the pockets 39 of the rotor 9 to permit passing thereof under the sealing faces I6 of the stator 8. As soon as the vanes 41 pass the sealing faces I6, they again swing outwardly to be engaged by a second jet of pressure fluid in the next pressure chamber and so on around the circumference of the stator. The pressure fluid is thus applied at a. plurality of points on each turn of the rotor to produce the required torque necessary lfor rotating of the bit.

The pressure iiuid exhausted from the rotor chambers passes through the exhaust channel I9 to the annular passageway 1I and is distributed to the ports 1G through the bit for discharge through the branch ports 12 for lubricating the drilling surfaces of the bits and carrying the cuttings inwardly toward the core passageway through the motor 6 and upwardly through the inner pipe 3 to the top of the bore hole.

As the drilling progresses, additional sections of inner and outer pipe 3 and 4 are applied to the sections. in the bore hole as in customary practice.

It is obvious that the power is applied substantially directly at the point of the bit 1 as a result that the pipes 3 and 4 need to resist only the reaction pressure of the motor, consequently lighter weight pipe may be used. It is also obvious that since the pressureis applied directly at the bott-cin oi the hole chatter and backlash of the bit is eliminated. Consequently, the drilling life of the bit is prolonged and a straighter hole is effected. It is obvious that as the drilling progresses, sections of the core are propelled upwardly through the central opening of the rotor and are discharged through the inner pipe 3 under the fiow pressure of the drilling fluid. In instances, where it is necessary to remove the core, this may be effected by running a socket member into the drill pipe by means of a cable to engage and lift the core out of the bore hole. Therefore, it is not necessary to remove the drill pipe and the drilling need be stopped only while the core is being engaged by the socket. Another feature is that only the body 33 of the rotor 9 and bit 1 are under rotation. All of the parts remain stationary. The vanes of course being carried by the rotor, swing to and from the rotor pocketsJ by their sliding movement over the surfaces !3, I5, I4, and I9 of the inner circumference of the stator.

It is also obvious that a free passageway is provided entirely through the motor and bit which permits running in and out of various instruments and other apparatus used in connection with drilling of a bore hole. When taking a core ahead of the bit, the small core barrel may be driven from the rotor of the motor by providing the barrel with keys that engage the inner longitudinal grooves 9 within the rotor.

It is further obvious that we have provided a motor construction which has a large axial passageway clear of any operating parts and Iwhich has a relatively small exterior when compared with the diameter of the passageway. This is made effective through the particular design of the vanes `and pressure chambers. Another feature is the power effected by the multiplicity of pressure chambers each being supplied with pre..- sure fluid which acts on all of the vanes as they pass through the respective chambers.

In the form of the invention illustrated in Fig. 9, the inner pipe 3 is connected with a flange 16 on the coupling ring 25 but the stator 8 is conrnected with the coupling in ithesame 4manner 4as inthe first described form of the invention. The `stator is :thus supported from rotation 4hy the inner .pipel. The outer:.pipe,-is-f1ee of .the-stator .but has'the lower end 17 thereof sleevediover the upperiendof the stator' andmay be shiftedirela- `tively'to the Vinner gpipe otherwise Vthe structure and operation isthe same asfin tneiirstdescribed Iorm of theinvention.

`What Vwe `claim .anddesire lto secureiby Letters Patent:

1. A core drilling apparatus including a .core blt `having an axial passagelfor a core and Aprovided with water courses, an inner string of drill pipe 'through which the 'core is adapted to be removed, a core barrel forminga downward continuation of the inner drill pipe and having a driving connection `with the core bit, an outer pipe coaxial with'the inner drill pipe and spaced therefrom to provide a downward ow passage therebetween for pressure fluid, a sleeve-like stator encircling the core barrel and having `fixed connection with one ci" `said pipes, said stator having circumerentially spaced elongated pressure chambers on the inner side thereof with the pressure chambers having inlet connections with the down ilow passage and exhaust connections with lthe water courses of the core bit, and vanes on the core barrel and arranged to move in and out or' the `Pressure chambers responsive `to flow .of pressure fluid for turning the core barrel to rotate said bit.

2. A core drillingapparatus including' a `core bit `having an axial `passage for a core and provided `with water courses, an inner string of drill pipe through which the core is adapted to be removed, aicore barrel forming a downward continuation of the inner drill pipe and having a driving connection with the core bit, an outer pipecoaxial'with the inner drill pipe and spaced therefrom to provide a downward ilow ypassage therebetween for pressure huid, a sleeve-like stator-encircling the core barrel, a coupling yconnecting the stator with the outer pipe and having an inwardly extending annular iiange engaging a-shoulder on the core barrel and provided i `with inlet ports, said stator having circumferentially spaced elongated pressure chambers on the innerside thereof with thepressurechambers in -connection with the inlet orts in said Iiange, a collar fixed tothe core barrel and engaging said ilange, said inner string of pipe having an `internal :flange cooperating withsa-id collar to provide bearing races, bearings vfor said races to journal the core barrel relatively to the inner -drill pipe, a coupling connected with the lower end of the stator and `having an inner flange closing the lower ends of the chambers vin encircling relation with the lower end of thecore 8 rbarrelat'thezeonnection of. saidcore bit and haviing exhaust ports `connected with `the water courses of the core ibit, and vanes on the `core barrel and arranged to move in and outofthe pressure chambers responsive to flow of preslsure vfluid for turning the core barrel to rotate :said fbit.

3. `Afdrilling apparatusiincluding a bit having .an.axial,passage and provided With water courses, :an innerstring ofdrill pipe, a fsleeve-likelrotor Vforming la downward continuation of 'the finner .drill Apipe/and having a 4driving connection `with thesbit, an-outer pipecoaxial with the rinner drill .pipeand spaced `therefrom to 'provide a downward vlovvpassagetherebetween forpressure'fiuid, ra sleeve-like stator .encircling-the rotor, a couplingconnecting the stator with .the outer pipe and'having an inwardly extending annular `flange engaging a shoulder .on the rotor and provided lwith yinlet ports, `said stator 'having circumferentially :spaced .elongated `pressure `chambers extending longitudinally on the inner sidethereof with ythe pressure chambersfin connection *with the inlet ports in said flange, a collar xedlto'the rotorandengagingsaid flange, said inner string of pipe :having an internal flange cooperating `with saidvcollar to provide bearing races therebetween, Ebearings forsaid races to journal the vrotor relatively to thefinner drill pipe, a coupling vconnected with the lower endlof the stator and having an inner Yflange closing the lower ends of the chambers in `encircling relation with the lower end of the rotor at saidconnection with the bit and havingexhaustports connected with the Water courses of the bit, and vanes on the rotor and arranged to move in and out of the pressure chambers `responsive to flow of pressure huid for turning the rotor to rotate said bit.

VERBOL J. DEVINE. .LAWRENCE V. DEVINE.

References Cited in the file of this patent UNITED STATES `Pit'IlJhl'lS Number Name `Date 873,056 Lake Dec. l0, 1907 945,209 Avery Jan. 4, 1910 961,849 Edwards et al June 2l, 1910 992,158'2 Olson May 16, 1911 1,453,683 -Kochendarier May 1, 1923 1,745,567 Crosse't al Feb. 4, 1930 2,002,387 Bannister May 21, `1935 2,254,641 Bannister Sept, 1941 `FOREIGN PATENTS Number Country Date 17,342 `Great Britain Nov. 28, 1888 349,859 France July 6, 1905 

